How can I draw a six graph together in one figure using plot and hold on?

I want to have six diagrams in different colors in one figure, but the program that I wrote only gives me one graph.

j=0;
for xi=0.01:0.02:0.11;
j=j+1;
    i1=0;
for bT=0.01:0.01:5
    i1=i1+1;
    
r=xi;
mass=1;
tn=bT; % période naturelle
wn=2.0*pi/tn; % pulsation naturelle

k=mass*wn^2; %Rigidité
wd=wn*sqrt(1-r^2); %Pulsation amortie

a=exp(-r*wn*dt)*(r*sin(wd*dt)/sqrt(1-r^2)+cos(wd*dt));
b=exp(-r*wn*dt)*(sin(wd*dt))/wd;
c2=((1-2*r^2)/(wd*dt)-r/sqrt(1-r^2))*sin(wd*dt)-(1+2*r/(wn*dt))*cos(wd*dt);
c=(1/k)*(2*r/(wn*dt)+exp(-r*wn*dt)*(c2));
d2=exp(-r*wn*dt)*((2.0*r^2-1)/(wd*dt)*sin(wd*dt)+2.0*r/(wn*dt)*cos(wd*dt));
d=(1/k)*(1-2.0*r/(wn*dt)+d2);
ad=-exp(-r*wn*dt)*wn*sin(wd*dt)/(sqrt(1-r^2));
bd=exp(-r*wn*dt)*(cos(wd*dt)-r*sin(wd*dt)/sqrt(1-r^2));
c1 = exp(-r*wn*dt)*((wn/sqrt(1-r^2)+r/(dt*sqrt(1-r^2)))*sin(wd*dt)+cos(wd*dt)/dt);
cd=(1/k)*(-1/dt+c1);
d1=exp(-r*wn*dt)*(r*sin(wd*dt)/sqrt(1-r^2)+cos(wd*dt));
dd=(1/(k*dt))*(1-d1);
for m=2:n1
u(m)=a*u(m-1)+b*v(m-1)+c*p(m-1)+d*p(m);
v(m)=ad*u(m-1)+bd*v(m-1)+cd*p(m-1)+dd*p(m);
ta(m)=(-2*r*wn*v(m)-wn*wn*u(m))/mass;
end
T(i1)=bT;
K(i1,j)=max(abs(u));
end
end
for Q=1,6;
plot(T,K(:,Q));
end

Answer 1

[Cris LaPierre]

Did you try to use hold? Also, your for loop syntax appears to be wrong. You also have several undefined variables.

hold on
for Q=1:6
    plot(T,K(:,Q));
end
hold off

[Meriem Noor]

How do I display different colors to the graph?

No i didn't know how to use holde before

I will correct the errors you mentioned

[Cris LaPierre]

See the Control Colors, Line Styles and Markers in Plots documentation page.

Also, see the Color section of the plot documentation page.

[Meriem Noor]

Thanks a lot for the help

Answer 2

[dpb]

Replace

for Q=1,6;
plot(T,K(:,Q));
end

with

hL=plot(T,K);

plot (like almost all MATLAB functions) operates by column and treats columns as independent variables.

To do one at a time explicitly (like if you were to plot() each when generated instead of waiting to the end), then you need a

hold on

statement either first or after the first call to plot() to add to the axes.

See

doc hold
doc plot

for details on each with examples.

[Meriem Noor]

Thanks a lot for the help